Electrostatic condenser



1, X July 1927' J. o. GARGAN 635.990

ELECTROSTATIC CONDENSER Filed A112. 2.6. 1924 hwy/fan- Ja/m Q6474,

Patented July UNI'rEo STATES PATENT; OFFICE.

, unta" o. GARGAN, or saooxnyn, NEW roux, ASSIGNOR T wnsrunn n nc'rmc com- Y many, moonronaren, or new YORK, N. Y., A. CORPORATION or-nnwyonx ELECTROSTATIC GOINDIICN'SEB.

Appliention filed August 26, 1924. Serial No. 734,194=.

Thi s intention relates to high voltage variable air condensers, tor use with radio broadcasting transmitters. 'lhoso condensers.

" are enerally mounted on, the backs of pane s, and consequently should occupy a little space as possible.

It has been the usual procedure in building these types or condensers to sup iort'thc movable plates on: a shaft. which is journalcd in hearings carried in front and rear plates,- the rear plate being cncrally secured to the hers outside of the movable plates, these members functioning solely as connecting members.

Since the capacity of an air'condcns'ertor agivon plate separation ar'ics directly as.- "the area of the plates, and th1s area 'varics directly as the square of the diameter, it is apparent that the space occupied by the connecting members, added to the clearances necessarily required to 'clea-r' the rotary plates, and, when mounted on the panel, to also clear adjacent apparatus, adds greatly to the area space requirements necessary to accommodate the condenser, While adding nothing to its efiective capacity area. In.

other words, the area occupied by these outer members and the necessary clearance often exceeds the area of the individual condenser plates themselves, due to the diameter squared effect.

In all air condensers aclearance space is left between the shaft and the stationary plates, out this oes not detract greatly from the cilective "Le a; because it is of comparatively iam- In the condenser ctthis invention, this clearance spacsis utilized for a singlcsupporting member for both the fixed and movable plates in the form of a spindle mounted a supporting base. The rotor hub slips over guide spindle and rotates on conical bearings at each-end of the rotor.

Since all the machining operations are confined to fitting a single hub on a solid spindle by means of conical bearings which 'automatioall act to take up play, the diili-' culties usua 1y. experienced in lining up hearings which are carried in separate momring oneor more teeth circumferentially and tion otthe condcnser'of this invention.-

trical-ly connected bythe bar-3, carry the sists in providing al fp'inion which, instead .of being the full widthof the gear', is only one-half of its width; This pinion carries on its hub a loose gear ring *of-the same width as the pinion. This loosering is secured to the pinion by a strong spring which opposes rotation: of the ring with respect to the pinion. By displacing the retaining this relationship avhen. meshing the pinion and ring With thegear'se'gment,1 front plate by a num' er of connecting-meme the 5 ring vis put under a tension whichsprcat s the two meshing teeth of the pinion? taking up all backlash.

Other features will tailed description.

Referring to the drawings,

Fig.1 a side elevation partially in -sec- Fig. 2 is a partial front iew showing the arrangement of arts; and

Fig 3 1S an-cn argcd'detailed viewof the gear arrangement for eliminating lfacklas'h-u The preierred' form ,of my invention shown in the drawings embodiestheprincipal essential features of the common type of variable air. condenser, comprising. in general two groups of spaced metal plates in alternate relation with a v a-i'iabledegree of overlapping to regulate the capacitatiye efiectr. I r' The parallel ring -members 1 and 2,-electwo opposite groups of stationary condenser plates 4: and'5, and are supported by the porcelain insulating elementsfi, 7, 8 and 9 which are attached by the cap screws l0. Insulators 6 and 7, are attached to the cen tral axis 11, comprising-therotor spindle l2 and'th'e supporting plate 13, which is screwed to the insulating plate 14, which in turn is attached to the panel hoard 15 by means of the bolts 16. and spaccs 17. circuits Where the movable plates are at ground potential, the condenser may be at-;

tachcd directly to a grounded metal plate,

' by means f inounting bolts in plate 13, dis-" appear dirom the d e it pcnsinp; wth insulating plate 14. Insulator support 18, to which the two insulators 8 and 9 are attached,i-is clamped againsta shoulder of spindle l2jby means of the cap screw 19 through ring. Washer 20 and electrical terminal washer fll;

thecoilthrust attached the t The rotor, comprising the hub 22 and the two groups of ametrically opposed con-' denser plates 23 and 24, is mounted on the spindle 12and rotates between the two bearing cones 25, and 26 which fit into the bevel seatprovided in both faces of the hub 22. Gone 25 is slipped over the spindle 12, makinga forced fit over a shoulder abutting member 11, while cone 26 is freely slidable axially but not rotatable on the spindle 12 and is held in position in its beveled seat by spring 27, which is recessed in a counterboredin 18. This arrangement rovi es a se justing positive cone t rust-bearing which eliminates axial and radial lay and the necessity a separate brush or making electrical contact to the rotor, since the bearings are ground to fit, making a relatively large contact surface. 1

A spur gear 28 is integral with one face of the hub 22 and meshes with a drivin pinion which consists of two halves29 an 30 on the insulated ksllligbft 31, (to hwhichd is urmng' 32 an t egm uated dial 33. The shait passes through an eye 34 on the member Hand is held in place by the ring and pin bearing arrangement 35. Referring to Fig. 3 which shows the "caring arrangement in detail, numeral 28 aesignates the driven s ur ear integral with the hub 22, and 2 an 30 the two through a manner halves of the drivin pinion. .Pinion 29 is rigidly attached to -t eshaft 31, while ring 30 is circumferentiall -movable thereon to an extent limited by t e spring 36, one end of which is rigidly fastened in the shaft 31 a diametral drill, as shown, where as the other end of the spring is attached to ring 30 by 'me'ans of the pin 37 in such that the spring opposes rotation of the ring with respect to the pinion; In

. assemblin the rin 30 is displaced one or more teet circum erentiallg' with respect to the pinion 29, and both t e ring and the pinion are then meshed with gear 28. The sprin 36 is-thus put under tension, which sprea the twomeshing teeth of the ring and pinion into fpositive contact with the opposite faces 0 the I inter-meshing spur r tooth space, thereby taking u all backfili, and, because the effect of t e spring pressure at the tooth slightly exceeds the tooth load, the gear can be driven in either direction without backlash.

In assembling the condenser of my invention, the rotor, which comprises the 90 t of sector plates 23 and 24 attached to t e rotor hub 22, is slipped over the rotor spindle 12, the symmetrical center lines of the respective movable and stationary; plates being at an angle of 90 with eac other as shown approximately in Fig. 2. The s ur r 28 on the hub 22 is meshed with the diismg pinion comprised of members 29'and 30 in the manner hereinbefore described, and the thrust bearin 26 with the spring 27 are slipped over t e spindle 12 and into position a inst the corresponding beveled recess in hu 22. The insulator support comprising the members 8, 9 and 18 IS an the washers 20 and 21 with the tap screw 19 complete the assembly. 4

i It will be understood that the above described apparatus has the same rinciple of operation as that of similar evices well known in the art, and, as before pointed out, the presentimprovement resides in the mechanical structure and arran ement of its parts. Since'all of the mac ining operations are confined to fitting a single hub on a solid spindle by means of conical bearings which automaticall take up axial and radial play, the diflicufties usually experiositioned by two of the tap screws 10,

enced 1n llIllIlg up bearings which are carried in se arate members are entirely eliminated an there is no,looseness whatever in the bearings. Furthermore, since, the capacity of an air condenser for a given plate separation varies directly as the area of the plates, and as this area varies directly as the square of the diameter, it is evident that the space commonly occupied by external con necting members and the like, added to the rotor plates, adds greatly to the area space requirements necessary to accommodate the condenser while addin nothing to its effective capacity area. ence, the area occupied by these outer members and the necessary clearances often exceeds the area of the individual condenser lates, due to the diameter squared eifect. i This condition is most pronounced on hi where large s acing 1s required to avoid voltage break owns; In the condenser ofmy invention the spindle .plates are electrically connected to their common su port and the centralaxial space is utilize for the insertion 'of the single su porting member for both fixed and mova-bfe plates in the form of a spindle integral with the base, thus economizing on space requirements for a given capacity.

The above description and the accompanying drawings illustrate the device in its preferred form, and slight variations in the design and structure of the several parts of the apparatus may be made without departing from the spirit or scope'of the'invention within the appended c ims.

What is claimed is:

1. In a variable air condenser, a supporting member, a frame mounted thereon, stationary condenser plates supported by said frame, other plates adapted to be moved in overlapping relation with the stationary plates, a spindle su ported b said member and supporting e mova Ie condenser gh voltage condensers clearances necessarily-required to clear the and plates, and a gearing device for rotating the movable plates on said spindle and including means for eliminating backlash.

2. An electrical air condenser comprising two groups each of fixed and movable condenser plates in alternate spaced relation and having a variable degree of overlap gearing for controlling said overlap, said gearing provided with back-lash elimmatim means, a frame, said two groups of fixed plates oppositely mounted on said frame, a spindle op. saidframe extending between said "maps, a rotor mounted on said spindle having said two groups of movable plates oppositely mounted thereon,said rotor turnable on said spindle by said gearing, and means between said spindle and said rotor for eliminating bearing play.

3. In a variable air condenser, the combination of a frame having a central spindle,-

fixed condenser plates attached to said frame, a rotor turnable on said spindle between axial cone thrust bearings, condenser plates supported. by said rotor and alter nately disposed between said fixed condenser plates, saidrotor having a variable angular displacement with respect to said fixed eondenser plates, said displacement effected by spur gearing, and said gearing having backlash eliminating means. i

t. An electrical air condenser comprising 'a single unitary mounting for both the stationary .and the movable plates consisting of a spindle integral with a frame, two

35 groups of superimposed stationary condenser plates oppositely fixed to said frame, a rotor turnab'le on said spindle between cone bearings, said rotor having two groups of superimposed condenser plates oppositely disposed and intermeshing with and variably overlapping said stationary condenser plates, gearing tor revolving said rotor, and

means for eliminating gearing.

5. In a variable air condenser, the combination of a mounting having a central spindle, a series of superimposed spaced stationary condenser plates supported from the mounting, a rotorturnable on said spindle between axial cone thrust bearings, a series of superimposed spaced condenser plates fixed to said rotor and alternately disposed between said stationary plates, said rotor having 'a spur gear meshing with a driving pinion, and said driving pinion having means for eliminating back-lash between the back-lash in said gear teeth by providing constant positive contact between "both faces of eachqinter meshing gear tooth space.

6. In a variable air condenser, a supporting member, a frame mounted on saidmember, stationary plates supported by said frame, a spindle extending from sai' memher, and a hub carrying the movable plates and adapted to slip in adjusted position on said spindle as a unit. I i

In witness whereof, I hereunto subscribe my name this 25th day of August, A, D,

JOHN O. GARGAN.

dill 

